Uncore Manual

Introduction
10 Reference Number: 329468-002
Notification after X events: . - instead of manually stopping the counters at intervals (often wall
clock time) pre-determined by software, hardware can be set to notify monitoring software when a set
number of events has occurred. The Overflow Enable bit is provided for just that purpose. See Section
2.1.1, “Counter Overflow” for more information on how to use this mechanism.
Applying a Threshold to Incoming Events: .thresh - since most counters can increment by a value
greater than 1, a threshold can be applied to generate an event based on the outcome of the compar-
ison. If the .thresh is set to a non-zero value, that value is compared against the incoming count for
that event in each cycle. If the incoming count is >= the threshold value, then the event count captured
in the data register will be incremented by 1.
Using the threshold field to generate additional events can be particularly useful when applied to a
queue occupancy count. For example, if a queue is known to contain eight entries, it may be useful to
know how often it contains 6 or more entries (i.e. Almost Full) or when it contains 1 or more entries
(i.e. Not Empty).
NOTE
For Intel
®
Xeon
®
Processor E5 v2 and E7 v2 Product Families the .edge_det bit follow
the threshold comparison in sequence. If a user wishes to apply these bits to events
that only increment by 1 per cycle, .thresh must be set to 0x1.
Counting State Transitions Instead of per-Cycle Events: .edge_det - Rather than accumulating
the raw count each cycle (for events that can increment by 1 per cycle), the register can capture tran-
sitions from no event to an event incoming (i.e. the ‘Rising Edge’).
1.5 UNCORE PMU SUMMARY TABLES
Following is a list of the registers provided in the Uncore for Performance Monitoring. It should be noted
that the Uncore Performance Monitors are split between MSR space (U, CBo and PCU) and PCICFG
space.
Table 1-2. MSR Space Uncore Performance Monitoring Registers
Box MSR Addresses Description
C-Box Counters
C-Box 14
0xED9-0xED6 Counter Registers
0xED4,0xEDA Counter Filters
0xED3-0xED0 Counter Config Registers
0xEC4 Box Control
C-Box 13
0xEB9-0xEB6 Counter Registers
0xEB4,0xEBA Counter Filters
0xEB3-0xEB0 Counter Config Registers
0xEA4 Box Control
C-Box 12
0xE99-0xE96 Counter Registers
0xE94,0xE9A Counter Filters
0xE93-0xE90 Counter Config Registers
0xE84 Box Control
C-Box 11
0xE79-0xE76 Counter Registers
0xE74,0xE7A Counter Filters